#pragma once
#include <string>
#include <iostream>
using namespace std;
class SalesItem
{
public:
	SalesItem();
	virtual ~SalesItem();

	string isbn();
	SalesItem& operator=(SalesItem& si);
	SalesItem& combine(SalesItem& si);
	void setDiscount(double discount);
	friend ostream& operator<<(ostream& os, SalesItem& si);
	friend istream& operator>>(istream& is, SalesItem& si);

private:
	string _bookNo;
	unsigned int _unitsSold = 0;
	double _sellingPrice = 0;
	double _salesPrice = 0;
	double _discount = 0;

};

